22974

TPX2

C20orf1|C20orf2|DIL-2|DIL2|FLS353|GD:C20orf1|HCA519|HCTP4|REPP86|p100;TPX2, microtubule-associated, homolog (Xenopus laevis);TPX2;TPX2, microtubule-associated, homolog (Xenopus laevis)

TPX2, microtubule-associated protein homolog|differentially expressed in cancerous and non-cancerous lung cells 2|differentially expressed in lung cells|hepatocellular carcinoma-associated antigen 519|preferentially expressed in colorectal cancer|protein

20q11.2

protein-coding

This study was undertaken to determine the prognostic relevance of the proliferation rate in neoplastic cells in children and adolescents with Hodgkin's lymphoma. Paraffin-embedded biopsy specimens were immunostained with the proliferation-associated monoclonal antibodies Ki-S5 (Ki-67 antigen) and Ki-S2 (which detects the repp86 protein). Repp86 is a protein of about 100 kDa encodedby a gene located on human chromosome band 20q11.2. In contrast to the Ki-67 antigen, repp86 expression is restricted to the cell cycle phases G(2), S and M.Immunohistochemical results on diagnostic lymph node biopsy specimens from 224 patients included in two pediatric multicenter Hodgkin's trials, GPOH HD-90 and HD-95, were compared with clinical data. High Ki-67 antigen expression was a striking feature of Hodgkin's and Reed-Sternberg cells as well as lymphocytic and histiocytic cells (median: 80%, range: 20-100%), in contrast to low repp86 expression (median: 20%, range: 10-80%; P<0.001). The proliferation rate was independent of histological subtype, stage and presence of B symptoms. The probability of event-free and overall survival (+/-standard error) of ALL patients at 5 years was 91.6+/-2.0 and 98.1+/-1.0%, respectively. The proliferation rate of tumor cells did not influence the outcome. The difference between Ki-67 and repp86 expression in Hodgkin's and Reed-Sternberg or lymphocytic and histiocytic cells points to a possible cell cycle arrest in the G(1) phase, which may explain the obvious paradox of a highly proliferating but slowly growing paucicellular tumor. High Ki-67 expression does not seem to be anadverse prognostic factor in pediatric and adolescent patients with Hodgkin's lymphoma treated by effective risk-adapted chemo-radiotherapy regimens.#CI- Modern Pathology (2005) 18, 1440-1447. doi:10.1038/modpathol.3800466; published online 29 July 2005.